Gas Outflows in Seyfert Galaxies: Effects of Star Formation Versus Agn Feedback

Abstract

Large scale, weakly collimated outflows are very common in galaxies with large infrared luminosities. In complex systems in particular, where intense star formation (SF) coexists with an active galactic nucleus (AGN), it is not clear yet from observations whether the SF, the AGN, or both are driving these outflows. Accreting supermassive black holes (SMBHs) are expected to influence their host galaxies through kinetic and radiative feedback processes, but in a Seyfert galaxy where the energy emitted in the nuclear region is comparable to that of the body of the galaxy, it is possible that stellar activity is also playing a key role in these processes. In order to achieve a better understanding of the mechanisms driving the gas evolution specially at the nuclear regions of these galaxies, we have performed high-resolution three-dimensional hydrodynamical simulations with radiative cooling considering the feedback from both star formation regions including supernova (type I and II) explosions and an AGN jet emerging from the central region of the active spiral galaxy. We computed the gas mass lost by the system, separating the role of each of these injection energy sources on the galaxy evolution and found that at scales within one kiloparsec an outflow can be generally established considering intense nuclear star formation only. The jet alone is unable to drive a massive gas outflow, although it can sporadically drag and accelerate clumps of the underlying outflow to very high velocities.

What powers the starburst activity of NGC 1068? Star-driven gravitational instabilities caught in the act

“…The central Σco(R) depression has instead no match in NGC 6946. For a galaxy with a massive AGN-driven outflow and intense starburst activity such as NGC 1068, it seems natural to associate the central Σco(R) depression with AGN/stellar feedback (e.g., Karouzos et al 2014;Storchi-Bergmann 2014;Agertz & Kravtsov 2015;Melioli & de Gouveia Dal Pino 2015;García-Burillo 2016;Hopkins et al 2016). However, as pointed out by the referee, other processes can contribute to the central Σco(R) depression, e.g.…”

Influência da formação estelar versus buracos negros de nucleos ativos de galaxias (AGN) na evolução de ventos galácticos

“…We have run all the models with a maximum resolution of 3.9 pc per cell with 256 3 resolution. Tests performed by Melioli and de Gouveia Dal Pino (2015) considering also simulations with 128 3 and 512 3 resolutions have indicated a good degree of convergence in the results for 256 3 resolution. For this reason, we have adopted this resolution in the present work.…”

“…The SFR is given in M yr −1 (log 10 scale), while the energy rates are given in units of 10 41 erg s −1 (log 10 scale). Extracted from Melioli and de Gouveia Dal Pino (2015) in Seyfert galaxies, where the nuclear source emits an amount of energy comparable to that of the body of the host galaxy, it would be possible that the outflows are driven by both processes, as remarked before, which therefore would imply that not only the AGN but also SF have a key role in the evolution of the system. In this study, we will consider both, i.e., a Seyfert galaxy which hosts a SB region and and an AGN SMBH as driving sources, and will study their feedback on the evolution of the galaxy and formation of the outflows at the kpc-parsec scale central regions (see below).…”

“…Motivated by the advances and unsolved questions in the studies described above, in this work, we have extended the previous study performed by Melioli and de Gouveia Dal Pino (2015) by adding new physical ingredients. In order to achieve a better understanding of the processes driving the nuclear gas evolution in a Seyfert galaxy, we perform fully 3D hydrodynamical (HD) and magnetohydrodynamical (MHD) simulations with (3.9 pc) resolution, taking into account the effects of magnetic fields, which have been neglected in the previous studies of Melioli and de Gouveia Dal Pino (2015) and Wagner et al (2012), and also the effects of the feedback of AGN winds with large opening angles.…”

“…Neste trabalho, estudamos como ambos podem influenciar a evolução da galáxia hospedeira e seus outflows, considerando galáxias tipo Seyfert nas escalas de kilo-parsec (kpc). Para este objetivo, estendemos o trabalho anterior desenvolvido por Melioli & de Gouveia Dal Pino (2015), que considerou ventos puramente hidrodinâmicos impulsionados tanto pela SF quanto pelo AGN, mas levando em conta para esteúltimo apenas ventos bem estreitos (colimados). A fim de obter uma melhor compreensão da influencia (feedback ) desses mecanismos sobre a evolução da galáxia e seus outflows, incluímos também os efeitos de ventos de AGN com maiorângulo de abertura, já que ventos em forma de cone podem melhorar a interação com o meio interestelar da galáxia e assim, empurrar mais gás nos outflows.…”